Field of the Disclosure
The present application relates to a touch sensing system. More particularly, the present application relates to touch sensing system and method capable of being efficiently switched from an idle state into a wake-up state.
Description of the Related Art
Most electrical appliances include a variety of internal and/or external input devices. Each of the electrical appliances inputs commands through the input devices and performs a variety of functions corresponding to the input commands. The input devices are variously implemented according to input modes. Representative examples of input devices, including a key pad, a mouse etc., are being used. Recently, touch panels (TSPS) are being increasingly used as the input devices. The touch panel inputs the command by sensing a touch position of a contact object.
In general, the touch panel is disposed on the surface of a display device, such as a cathode ray tube (CRT), a liquid crystal display (LCD) device, a plasma display panel (PDP), an electroluminescent (EL) device or other devices, in order to sense a touch position of a contact object. An input device using the touch panel can input a command from a user by enabling the user to touch a fixed position of the touch panel with a contact object, such as a finger, a stylus pen or others.
If the touch panel is touched in an idle state that a system is not driven, the touch panel detects whether or not it is touched, and enables the system to be switched from the idle state into a wake-up state according the detected resultant. In accordance therewith, the system operates in a normal state.
However, a touch sensing system of the related art for detecting whether or not the touch panel is touched must perform a touch sensing operation only in the wake-up state, which is periodically set in a fixed lengthy interval by a software. Due to this, power consumption of the related art touch sensing system must increase.
Also, the related art touch sensing system with the touch panel performs the detection of a touch using only a fixed reference data. Meanwhile, an in-cell touch panel becomes weaker against noises according to temperature rise and external environment change, due to its structure of including an internal capacitor.
The noises can cause a sensing level deviation between nodes on the in-cell touch panel. Also, a detention error must be generated at a fixed node due to the sensing level deviation. Due to this, reliability of the in-cell touch panel for the touch detection must deteriorate.